The demand for increased storage capacity in memory or rigid disks and the trend towards miniaturization of memory or rigid disks (due to the requirement for smaller hard drives in computer equipment) continues to emphasize the importance of the memory or rigid disk manufacturing process, including the planarization or polishing of such disks for ensuring maximal performance. While there exist several chemical-mechanical polishing (CMP) compositions and methods for use in conjunction with semiconductor device manufacture, few conventional CMP methods or commercially available CMP compositions are well-suited for the planarization or polishing of memory or rigid disks.
The term “memory or rigid disk” refers to any magnetic disk, hard disk, rigid disk, or memory disk for retaining information in electromagnetic form. The memory or rigid disk typically has a surface that comprises nickel-phosphorus, but the memory or rigid disk surface can comprise any other suitable material. The planarity of the memory or rigid disks must be improved, as the distance between the recording head of a disk drive and the surface of the memory or rigid disk has decreased with improvements in recording density that demand a lower flying height of the magnetic head with respect to the memory or rigid disk. In order to permit a lower flying height of the magnetic head, improvements to the surface finish of the memory or rigid disk are required.
Improvements to the surface finish of the memory or rigid disk require the reduction of scratches and micro defects caused by abrasive particles. It has been hypothesized that frictional forces generated between a polishing pad and a substrate being polished leads to increased scratching and micro defects. However, the presence of additives intended to reduce frictional forces typically leads to agglomeration of abrasive particles, with a consequent increase in scratching and micro defects. Accordingly, there is a need in the art for polishing compositions exhibiting reduced scratching and micro defects and also exhibiting good surface topography and practical removal rates.